It is fairly common to have some scripts that use repository information, for example, builds or release note generation. This small example will show some examples of the rev-parse command that can be very useful for scripting.
Clone the data-model repository from Chapter 1, Navigating Git:
$ git clone https://github.com/dvaske/data-model.git $ cd data-model
First, let's figure out the ID of the commit at HEAD:
$ git rev-parse HEAD 34acc370b4d6ae53f051255680feaefaf7f7850d
This can, of course, also be obtained by git log -1 --format=%H, but with the rev-parse command, you don't need all the options. We can also get the current branch from the rev-parse command:
$ git rev-parse --symbolic-full-name HEAD refs/heads/master
We can also just get the abbreviated name:
$ git rev-parse --symbolic-full-name --abbrev-ref HEAD master
We can also get the ID of other refs:
$ git rev-parse origin/feature/2 82cd5662900a50063ff4bb790539fe4a6d470d56...